Definition
The moment during the takeoff roll at which an aircraft's wings produce enough lift to overcome its weight and the aircraft leaves the runway surface.
Plain English
The instant the wheels leave the ground during takeoff and the aircraft starts flying.
Context Anchor
Used during takeoff, especially when discussing takeoff technique, runway distance, and the point where the aircraft first leaves the runway.
Derivation
Combines 'lift,' from the Old English word for raising upward, with 'off' to indicate leaving the surface. This origin highlights the transition from ground contact to flight.
Why Pilots Care
Determines required runway length and is used in calculating safe takeoff performance.
Grounding Statement
During takeoff, lift off is the instant the wheels leave the runway.
Intuition Check
Lift off does not mean the whole takeoff is complete. It means the aircraft has just left the surface and is now airborne.
Example Sentence 1
The instructor called out the airspeed as the aircraft accelerated, and lift-off occurred smoothly at 65 knots.
Example Sentence 2
On a hot day, higher density altitude delayed lift off until farther down the runway.